A table device was proposed some years ago, which is adapted to move a table, on which a material to be processed or measured is placed, in two directions which cross each other at right angles, so as to position such a material accurately in a machining tool or a measuring apparatus. The driving means for this table device include a driving means disclosed in Japanese Patent Laid-open No. 18711/1983 dated Feb. 3, 1983 and entitled "XY table", which driving means consists of a linear motor connected to a table via a joint; and a driving means disclosed in "These Published in the Spring Science Lecture Meeting Held by the Learned Circle of Precision Machines in 1982" published on Mar. 22, 1982, pages 207-209, "Finely Positioning Mechanism for Static Pressure Air-Floated Stages", which consists of cross guides extending at right angles to each other and connected to a table, and a linear motor operated on the cross guides.
In the former table driving means, the driving force of a linear motor is transmitted to a table through a joint having backlash. Therefore, the transmission of the driving force is delayed due to the backlash of the joint. In the latter table driving means, the driving force of a linear motor is applied to the cross guide which is positioned away from a table. Accordingly, when a material to be processed is placed on the table or on an eccentric portion thereof, the cross guide yaws, so that it takes time to stabilize the cross guide. As may be clear from the above, these two table driving means require a long settling time in which the table is set in a predetermined position. Hence, it is very difficult to attain the speedup of a positioning operation by these table driving means.